规避预处理的隐写载体选择

在隐写术流程中,载体的选择在很大程度上影响着隐写系统的安全性。实验表明,经过预处理后的图像在用于隐写嵌入后会导致隐写安全性大幅降低。当给出较多备选图像时,可以选取多张图像用于进行隐写来提升隐写系统安全性。利用深度神经网络模型筛选出备选图像中已被预处理过的图像,根据深度神经网络输出赋予备选图像预处理失真,并结合传统的嵌入失真算法选择出最适合隐写的多幅图像进行隐写。与其他多载体隐写载体选择方案相比,所提出的载体选择方案在备选图像中含有预处理图像的情形下有着较好的表现,能够显著提升隐写系统安全性。

Multiresolution Fusion of Remote Sensing Images Based on Resolution Degradation Model

A new method based on resolution degradation model is proposed to improve both spatial and spectral quality of the synthetic images. Some ETM+ panchromatic and multispectral images are used to assess the new method. Its spatial and spectral effects are evaluated by qualitative and quantitative measures and the results are compared with those of IHS, PCA, Brovey, OWT(Orthogonal Wavelet Transform) and RWT(Redundant Wavelet Transform). The results show that the new method can keep almost the same spatial resolution as the panchromatic images, and the spectral effect of the new method is as good as those of wavelet-based methods.